Piston rod connection



A ril 16, 1935. c. E. MELKE 1,997,884v

P ISTON ROD CONNECTION Fi led May 16, 1934 Z2 Z3 g Patented Apr;

UNITED STATES PATENT OFFICE PISTON R01) CONNECTION Charles E.Melker,'Hannibal, Mo. Application May 16, 1934, serial No. 725,871

' 7 Claims. (o1.2s7-119) The present invention relates to piston rodconnections.

In connecting piston rods to crossheads, parparts in rigid rel Theprovision of t ationship with one another. heykeyway for the crossheadkeyhas weakened the construction. Piston rods or crossheads have cessiveforce. which has been exerted in driving the keys home. Moreover,according to the prior practice referred to, it has been a difficult andunsatisfactory operation to remove the piston rod from the crosshead.

An object. of the present invention is to provide a construction ofpiston rod and crosshead which Will-have'the advantages of strongconstruction combined Withlight Weight.

A.further object is to provide a piston rod connection which willeliminate the use of crosshead keys, with the attendant advantage thatkeyways will be unnecessary. s 1

A further object is to provide a piston rod connection in. which firmlongitudinal bearings may be had at-at least two points along the pistonrod, resulting in improved rigidity.

A further object is to provide a pistonrod connection which avoidsdriving tapered fits and the use of crosshead keys.

' ease and may be r sired;

eadily disassembled when 'de- A further object is to provide an improvedconstruction connecting apiston rod or other elongated memb er to acrosshead or the like in which the members have broad bearingcooperating surfaces at at least two points disposed or in disassemblingsaid members. 'j

- Further objects will appear as the description proceeds.

Referring to the drawing Figure 1 is a 'view in elevation of a crossheadand pistonrodembodying the principles of the present invention;

Figure 2 is a view partly in section, taken along 'the planes indicatedby the arrows 22 of Figure 1;

Figure 3 is a lon gitudinal sectional view taken along the planeindicated by the arrows 3-3 of Figure 1; 1

Figure 4 is a view on an enlarged scale showing a detail ofconstruction; and

Figure 5 is an end View of a collar Wrench forming a detail of thestructure shown in Figure 4. l

The numeral It indicates a crosshead and the numeral N indicates apiston rod. Said piston rod H has its end surface l2 normal to thelongitudinal axis of said rod and is provided adjacent to but spacedfrom the end [2 with the annular shoulder 53, which shoulder has thesurface Hl parallel with the end surface l2 of the piston rod. Spacedbetween the shoulder l3 and the end surface I2 is a series ofinterrupted threads l5. Expressed in other language, said members i5l5are spirally disposed splines, three of said splines being disposedWithin a range of 360 degrees, Said splines I5l5 register witheach'other longitudinally of the piston rod H.

The crosshead i0 is provided with the portion 16 apertured, as indicatedby the numeral 5a,

' r are spirally disposed with respect to one another and spaced apartspirally a sufficient distance to receive the spirally disposed splinesI 5l5 of the crosshead H. The portionlfi of the crosshead I0 is providedwith the plane surface It adapted to provide a bearing surfacefor'thecooperating face 14 of the shoulder l3 of the piston rod' II. The endsurface [2 of thepiston rod ll engages flatwise with the bottom of thecooperating aperture Mia. in the crosshead l9.

The shoulder [3 of the piston rod l I is provided with a pair ofdiametrically opposed notches l9"l9. Disposed upon said shoulder is acollar 20 having a pair of diametrically opposed teeth 2l--2l fittinginto the notches I9--I9 in the shoulder 13. The'collar 2! is provided atdiametrically opposed regions adjacent to the teeth Zi-Zl with a pair ofbifurcated lugs 2222,

which bifurcated lugs carry pins Z323. Each in Figure 4. Each of saideye-bolts is provided with another nut 27 disposed between thecorresponding lug 22 and the corresponding shoulder 25. Each of saidnuts 21 is adapted to be turned up into engagement with itscorresponding shoulder 25. The collar 26 may be recessed as indicated bythe numerals 28-28 to permit the bolts 24-24 to enter the apertures inthe lugs 25-25 as said collar 29 is turned in a clockwise direction asthe parts are viewed in Figure 4.

The mode of operation or the above described embodiment of the presentinvention is substantially as follows: Ihe piston rod 5 i will beassembled to the crosshead it by inserting said piston rod with thesplines iii-l5 thereof disposed in alignment with the spaces between thesplines l'l-l'! of the portion 58 of the crosshead it. When said pistonrod l i has been inserted longitudinally into said portion IS apredetermineddistance, said piston rod will be turned. As the parts areillustrated, aclockwise direction of rotation of the piston rod i i (asthe parts are viewed in Figures '2 and 4) will result in the screwinghome of said piston rod vl l. The shoulder i3 and the end face E2 of thepiston rod l i should be so positioned relative to the splines l5-i5thereof and with respect to the face 18 and the bottom of the aperturein the portion 16, as well as the splines 17-, that said piston rod l ishould bottom itself at substantially the same instant that the face Mof the shoulder 53 engages the face l8. At this instant the splinesi..-!5 should preferably be in aligned position with relation to thesplines l'I-l'l, or should be approaching such aligned position. Inother words, when the connecting rod 4 I has been inserted into theportion iii of the crosshead and has been given substantially one-sixthof a turn, said connecting rod II should be securely bottomed in thecrosshead, the shoulder l3 should be in intimate engagement with theface l8 of the crosshead, and the splines l5-I 5 on the piston rod I Ishould be completely or almost completely enmeshed with the splinesI'I-I'I.

While the piston rod H is being turned into home position, as abovedescribed, the collar wrench 20 will be disposed upon the shoulder 13with the teeth 2l-2l of said collar wrench located within the notchesIii-l9 of the shoulder 13. At this time the nuts 23-26 will be removedfrom the eye-bolts 24-24 and the swinging extremities of said eye-bolts24-24 will be inserted through the apertures in the lugs 25-25. As thepiston rod H is turned home, said eye-bolts 24-24 will be thrust throughsaid lugs 25-25. The apertures in said lugs 25-25 will, of course, besufficiently large to permit a slight angular movement in each eye-boltas the piston rod moves longitudinally while it is being screwed homeand to permit a slight swinging movement of the eye-bolts 24-24 as thelugs 22-22 are moved circumferentially. The nuts 25-26 will then bethreaded upon the eye-bolts 24-24 and the piston rod will be heldsecurely against counterclockwise movement as the parts are viewed inFigure 4 by reason of the engagement of the nuts 26-26 with the lugs25-25. The nuts 21-21 will be turned up to engage the other sides of thelugs 25-25 whereby the parts will be held in rigid relationship.

When it is desired to disassemble the piston rod I I from the crossheadHi, the nuts 26-26 will be backed off and the nuts 27-21 will be turnedto exert astrong thrust against the lugs 25-25 to loosen the piston rodll from-the crosshead lfl, whereby said piston rod H maybe turned to aposition in which the splines 55-15 thereof are out of registry with thesplines l-l'l, after which the piston rod H may be moved outlongitudinally to a position free of said crosshead It.

By reason of the present invention a construction is provided in whichlongitudinal end thrust of the piston rod is taken by two bearingsurfaces embodied in the end face I2 of the piston rod and the face [4of the shoulder l3 of said piston rod. The home position of the pistonrod is maintained by reason of the engagement of the nuts 26-26 withtheir corresponding lugs 25-25, whereby an absolutely rigid constructionis had without the use of crosshead keys and their correspondingkeyways. Disassembling of the piston rod l i from the crosshead 10 maybe accomplished without the use of blows, which are so frequentlydestructive in other constructions, which blows are necessary inremoving the crosshead keys and in loosening the piston rodfroin thecrosshead.

Though a preferred embodiment of the present invention has beendescribed in detail, many modifications will occur to those skilled inthe art. It is intended to cover all such modifications that fall withinthe scope of the appended claims.

What is claimed is- I. In combination, a piston rod member, a crossheadmember, said piston rod member having a plurality of spirally disposedsplines thereon, said crosshead member having'an'aperture with spirallydisposed splines therein, the splines of said pistonrod' member beingspaced apart spirally, the splines of said crosshead member being spacedapart spirally a distance suflicient said spirally disposed splines, acrosshead memher having an aperture for receiving the splined portion ofsaid piston rod member, said crosshead member having inwardly projectingspirally disposed splines, which splines are spaced apart a suiiicientdistance to receive the splines of said piston rod member, said membershaving bearing surfaces for taking up end thrust between said members,one of said members having holding means provided with a swinging bolt,the other of said members being provided with an apertured portion forreceiving said bolt, and nuts on said bolt disposed on opposite sides ofsaid apertured portion for controlling rotary movement of said membersrelative to one another.

3. In combination, a first member having a series of spirally disposedsplines thereon, said splines being spaced apart and in registry withone another longitudinally of the axis of said spirally disposedsplines, said second member having an aperture for receiving the splinedportion of said first member, said second member having inwardlyprojecting spirally disposed splines, which splines are spaced apart asuincient distance to receive the splines of said first member, saidmembers having bearing surfaces for taking up end thrust between saidmembers, one or" said members having holding means provided with aplurality of swinging bolts, the other of saidmembers being providedwith a plurality of apertured portions for receiving said bolts, andnuts on each of said bolts disposed on opposite sides of theircorresponding apertured portions for controlling rotary movement of saidmembers relative to one another.

4. In combination,'a crosshead member having an apertured portion, apiston rod member, v

said piston rod member having near one of its ends a series of spirallydisposed splines, said splines being spaced circumferentially and beingin registry longitudinally of said piston rod member, said crossheadmember in said apertured portion having a series of cooperating splines,

said crosshead member having a shoulder and a flat end face adapted tobear against corresponding surfaces of said crosshead member, one ofsaid members having holding means provided with a swinging bolt, theother of said members being provided with an apertured portion forreceiving said bolt, and nuts on said bolt disposed on opposite sides ofsaid apertured portions for controlling rotary movement of said membersrelative to one another.

In combination, a crosshead member having an apertured portion, a pistonrod member, said piston rod member having near one of its ends a seriesof spirally disposed splines, said splines being spacedoircumferentially and being in registry longitudinally of said pistonrod member, said crosshead member in said apertured portion having aseries of cooperating splines, said crosshead member having a shoulderand a fiat end face adapted to bear against corresponding surfaces ofsaid crosshead member, and

threaded means for preventing relative rotative movement between saidpiston rod member and said crosshead member, said threaded meansincluding a pair of swingable bolts carried by one of said members andnuts thereon cooperating with abutments fixed to the other of saidmembers.

6. In combination, a crosshead member, a piston rod member, said membershaving cooperating interrupted splines for holding said members againstdisplacement longitudinally, said members having a pair of spaced apartcooperating bearing surfaces for taking up end thrust between saidmembers, a collar upon one of said members having toothed engagementwith said one membena pair of swingable bolts carried by said collar,abutments on the other of said members for receiving said bolts, andnutsupon said bolts cooperating with said abutments for controlling relativerotative movement between said members.

7. In combination, a crosshead, a piston rod adapted to be inserted intosaid crosshead, said piston rod and said crosshead having cooperatinginterrupted spirally disposed splines, a shoulder on said piston rod, acollar wrench upon said shoulder, said collar wrench having toothed en-7 relative rotative movement between saidcrosshead and said piston rod.7

CHARLES E. MELKER.

